Axolotl (Ambystoma Mexicanum) - Animals - A-Z Animals Five groups that classify all living things Animalia A group of animals within the animal kingdom Chordata A group of animals within a pylum Amphibia A group of animals within a class Caudata A group of animals within an order Ambystomatidae A group of animals within a family Ambystoma Comprised of the genus followed by the species Ambystoma Mexicanum The animal group that the species belongs to Amphibian What kind of foods the animal eats Carnivore How long (L) or tall (H) the animal is 15cm - 45cm (6in - 18in) The measurement of how heavy the animal is 60g - 200g (2oz - 7oz) The fastest recorded speed of the animal 17km/h (10mph) How long the animal lives for 10 - 20 years Whether the animal is solitary or sociable Solitary The likelihood of the animal becoming extinct Endangered The colour of the animal's coat or markings Black, White, Pink, Grey, Brown The protective layer of the animal Permeable The specific area where the animal lives

 High altitude freshwater lakes The average number of babies born at once 500 Other animals that hunt and eat the animal Birds, Fish Characteristics unique to the animal Feathery gills and flattened-shaped head Axolotl Location Map of South America Axolotl The axolotl is a medium-sized amphibian that is only found in one complex of lakes that are close to Mexico City in south-central Mexico .

The axolotl is today kept as a popular freshwater aquarium pet all around the world. The axolotl is most closely related to the tiger salamander which inhabits the waters in a similar region of Mexico . However, axolotls can be easily distinguished from salamanders as the axolotl retains it\'s tadpole-like appearance for it\'s whole life, therefore axolotls and young tiger salamanders are easily confused. The axolotl has a flat-shaped broad head that is much wider than the body of the axolotl . The axolotl also has feathery gills which protrude from either side of the head of the axolotl , allowing the axolotl to breath under water. As with newts and salamanders , axolotls are able to regenerate limbs that become damaged or detached meaning that axolotls have been extensively used in scientific experiments around the world. The axolotl is most commonly found in albino form as they spend a great deal of their lives hiding under rocks and in crevices on the bottom of the lake.

Although axolotls are generally white or pink in colour , black, grey and brown coloured axolotls can also be found. The axolotl is a carnivorous animal meaning that the axolotl has a purely meat-based diet . The axolotl eats worms and insect larvae that develop under the surface of the water along with molluscs , crustaceans and some small species of fish. Due to the bottom-dwelling lifestyle of the axolotl , it has surprisingly few natural predators despite it\'s relatively small size . Birds and large fish are the most common predators of the axolotl along with humans who catch the axolotl to keep as pets in artificial environments. The axolotl can live for up to 25 years although the average axolotl rarely gets much older than the age of 15. Female axolotls can lay anywhere from 100 to 1,000 eggs which are coated with a sticky substance that helps them to stick to plants and rocks in the water to keep them safe. After about a month of development, tiny axolotl babies emerge into the open water.

Today, the axolotl is considered to be a critically endangered species meaning that there are very few axolotl individuals left in the wild. Increasing levels of pollution is the most destructive factor in the survival to the axolotl with the ever-growing size of nearby Mexico City. Share This Article The Axolotl. The fish that walks? - creation.com by Jeffrey Dykes Used with permission Upon looking at an axolotl for the first time, one might wonder exactly what kind of creature it is. With its catfish-like shape, the odd, frilly appen­dages emanating from its neck, and its fins, limbs and feet, should it be classified land- or water-dweller? It has gills, and can clearly breathe underwater. But watching it walk across the bottom of an aquarium tank, it is no surprise that it is commonly referred to as the ‘Mexican walking fish’. So should evolutionists take heart that here is something like a living ‘transitional form’, perhaps on its way to evolving from a fish to an amphibian? Not at all. The axolotl is, in fact, a salamander, placed in the same amphibian group with frogs and toads.

Like all amphibians (and unlike all fish), the limbs are firmly attached to the vertebral column. Its scientific name is Ambystoma mexicanum. The name ‘axolotl’ is derived from the Aztec nahuatl, which means ‘water dog’. As an adult, the axolotl can reach a length of up to 30 cm (12 inches) and weigh over 300 g (10 ounces), making it a fairly sizeable amphibian. It tends to have a light cream to tan colouration in captivity, with a more mottled black-and-green colouration in the wild. But it can also appear tan, grey, brown, albino or even transparent (so one can see its internal organs). If properly cared for, it can live for up to 12 years. An amazing ability of the axolotl is its fantastic regeneration and healing capabilities Axolotls eat mainly worms, snails, assorted crustaceans and small fish. 1 Their jaws contain fine teeth, which are used only for gripping their prey, which they swallow whole. They can be cannibalistic toward each other as juveniles, so care should be taken when keeping them in captivity.

Upon reaching maturity, the female can lay up to 1,000 eggs every 3–6 months. 2 This odd amphibian is quite rare in the wild, existing in only one place in the world—Lake Xochimilco in Mexico (see map opposite page). Realizing this, the Mexican government has protected the area around the lake in order to preserve the axolotl. Fortunately, it breeds well in captivity, so though it is on the CITES 3 list of endangered species, there are enough specimens in captivity worldwide to ensure its survival. Incredible recuperative powers Though people and most animals are able to sufficiently heal a cut, replace portions of dead or damaged skin, or even regenerate a small part of an internal organ, axolotls are virtually unique among vertebrates in that they can completely regenerate entire limbs and organs. Instead of merely forming scar tissue over a wound, as most vertebrates do when healing, the axolotl can regenerate entire body parts, including whole limbs, gills, eyes, kidneys, even large portions of its liver and its heart muscle.

If it loses its tail, it can eventually replace it—skin, muscle and all.1 Even portions of its spine and brain can be regenerated, something which is a near-impossibility with almost every other vertebrate. Parts of other axolotl embryos can even be spliced onto others. Juvenile axolotls seem to be able to regenerate body parts quickly, while adults either replace parts more slowly or not at all. However, once an axolotl metamorphoses into a land animal, whether naturally or artificially, it can no longer regenerate as it could in its larval state.2 Inset image: Logan City Pet Country, This email address is being protected from spambots. You need JavaScript enabled to view it. References Eng, C., Axolotl health, < mite/4301/axolotlhealth.htm>, 8 December 2004. Pickin, L., Keeping axolotls , 8 December 2004. An amazing ability of the axolotl is its fantastic regeneration and healing capabilities (see box at left). It can replace significant portions of its body if damaged.

For this reason captive-bred individuals are extensively used in laboratory testing, as scientists have hoped to unlock the secrets of its radical healing abilities. By far the most unusual aspect of this salamander is that it retains its larval form into adulthood. So, unlike most amphibians, which metamorphose from water- to land-dwelling as they grow, the axolotl retains its gills and fins instead of exchanging them for developed lungs and limbs. This abbreviated developmental condition is known as ‘neoteny’, and the axolotl both thrives and breeds in its larval state. Stranger still, it can be forced to complete its larval stage and transform into a normal adult salamander by applying the metabolic hormone thyroxine. 4 This causes the gills to be absorbed into the body and the lungs to fully develop, as well as causing the eyes to develop eyelids like surface-dwelling animals. It can also transform itself if it leaves its watery environment for an extended period of time, especially if its surroundings are too dry. Evolutionists sometimes refer to the stunted, normal adult form of the axolotl as a ‘backward step in evolution’.

Supposedly, this amphibian was originally a largely land-dwelling salamander. Instead of going onwards to evolve into reptiles (then mammals, as the belief goes), one group of these allegedly returned to the water in a gradual fashion and are now caught in-between stages of development. However, the evolutionary literature is oddly reticent about exactly how or why this happened. The creature would have had to abandon the alleged advantages of leaving the water to begin with. This is an excerpt from the HEMA Central America and the Caribbean map Lake Xochimilco is situated within the suburban area of Mexico City and is the world’s only known natural habitat for axolotls. (click image for larger view) As far as the facts go, axolotls have fully-formed limbs, gills, eyes, etc., and these function perfectly adequately for their purposes. The unusual features of the axolotl also present no problem to creationists. Since it can breed with certain other species of amphibian, such as the tiger salamander, 5 it certainly would have come from the same original created kind as these. In fact, by the usual scientific definition, the two should be placed in the same biological species.

If the characteristics peculiar to the axolotl did occur, say, from changes through its surroundings after it was created, then these changes only sorted out and relied on information and mechanisms already present in the animal; no additional information was added. It is possible that the selective effects of the isolation of its gene pool (particularly considering that the axolotl is so isolated in Mexico) caused its arrested development. This separation might have occurred immediately after the Flood, when the waters receded and stranded different aquatic animals in lakes around the world. Interestingly, it is also entirely possible that axolotls were not included on Noah’s Ark , as they are largely water-dwelling creatures. So this particular species of amphibian could have survived the Flood without being included in the basic kinds taken aboard the Ark. Axolotls (and many other types of amphibian) could have survived on surface debris, floating mats of vegetation, or driftwood (of which there were undoubtedly great amounts). 6 If, during the Flood, the axolotl was in the form that it is today, then it very likely could have survived the Flood totally submerged without any adverse effects.

Transforming from water to land If the conditions are right, a mature, adult axolotl can spon­taneously metamorphose from a water-dwelling animal to a land-dwelling one. Over a period of up to several weeks, it will gradually absorb its gills back into its body, while its rudimentary lungs are simultaneously strengthened and enlarged so they can breathe oxygen from the atmosphere. Also, its tail changes from being flattened like a tadpole's to being more rounded like that of a true adult salamander. Its skin becomes tougher and dryer as it begins to adapt to living out of water, and it will also moult its skin as a surface-dweller. Eventually, its eyes will begin to bulge out and develop eyelids, while its skin will often become more vivid and colourful after it makes its terrestrial transformation. Unfortunately, axolotls which make the incredible transition to land as an adult often experience a shortened lifespan, presumably due to the stress of transformation. Of course, this amazing change has nothing to do with evolution; the potential for it is all there, preprogrammed in its genes. Inset image: Logan City Pet Country, This email address is being protected from spambots.

You need JavaScript enabled to view it. Related Articles Axolotl | Chapter 1 - What is an Axolotl? Chapter 1 – What is an Axolotl? The axolotl is an amphibious salamander (Ambystoma mexicanum), indigenous to Mexico. Sometimes called a “water monster” or Mexican Walking Fish, its name is derived from the Aztec language Nahuatl. The closest translation in English is “water dog.” These unique creatures were once considered to be a culinary delicacy. They are mole salamanders, and are among the most primitive of their kind, diverging from other salamanders in their development more than 140 million years ago. This fact is only the first in a long list of items that make the axolotl a truly unique creature. The first specimens appeared in Europe in 1863. Today, axolotls are rarely caught in the wild and are listed as a CITES endangered species. Axolotls are, however, widely bred in captivity for their value in medical research involving limb regeneration, trauma, and anti-aging.

Additionally, the large size of the species’ embryos makes them useful in a broad range of disease-related studies. Hobbyists find the axolotl an intriguing choice among the many aquatic creatures that can be successfully housed in an aquarium. While fully-grown axolotls will live peacefully with one another, they can exhibit cannibalism when they are younger. The axolotl is a fully aquatic species. They cannot survive out of water, and they are neotenous, meaning they remain in their larval form for life. Axolotls are Neotenous The reasons for the axolotl’s neotenous state are not clear. It may be a result of the species development in waters with insufficient stores of iodine. This would compromise the presence of the hormone thyroxine in the salamander’s body and keep it permanently in its larval state. Another theory suggests that water temperature may prevent the thyroxine from functioning appropriately. Some experts even believe the axolotl de-evolved to a fully aquatic state because they were safer in the water than on land, a theory that extends to other species that naturally live in bodies of water at high elevations.

The axolotl has gills and fins, with only rudimentary lungs. The gills are, in fact, one of its most prominent features, rising in feathered pairs on either side of the salamander’s head. Technically called “rami,” the gills are full of capillaries or “fimbrea.” As a neotenous life form, the axolotl is regarded as a backward step in evolutionary terms. It is thought to be an offshoot of the Tiger Salamander, a species with which the axolotl can breed successfully. (For more information about the Tiger Salamander, See Appendix 1). If an axolotl is treated with hormones, it will metamorphose, but this rarely happens spontaneously. Claims by enthusiasts online that they have a creature that has done so are almost always a case of mistaken identity with a Tiger Salamander. Physical Characteristics of the Axolotl An adult axolotl measures 7-14 inches (18-35 cm). They are poikilothermic, meaning that their body temperature is completely dependent on their surroundings. Temperature is, in fact, highly important in their care.

They do not tolerate temperature fluctuations and need colder water than tropical fish. Feathered Gills and Breathing Their prominent and feather-like gills are highly functional breathing systems. The gills pull water through their membranous structure so the capillaries can extract oxygen from the liquid and feed it into the body. In turn, the gills also pass waste carbon monoxide back into the water. The axolotl does not need to move for its gills to function. The structures move or wave gently on their own to perform their oxygen-gathering function. The gills are obviously very fragile, but even if they are harmed, the salamander can still breathe quite well. The gills grow back quickly, and the axolotl actually has “back up” breathing systems. Other Forms of Respiration In addition to the use of its gills, axolotls are capable of cutaneous respiration. When the salamander moves, or when the water itself moves, oxygen passes through the creature’s thin skin and into its body. Too much motion in the water, however, will stress an axolotl to the point of death.

Finally, axolotls also use buccal respiration via a flap at the back of the throat, the buccopharyngeal membrane. When water passes over the structure, oxygen is extracted. The same membrane functions to allow the axolotl to suck water into its mouth for feeding. Although not sufficient to sustain breathing for long, the axolotl does have very primitive lungs. They can “sip” air at the surface, but more times than not, this does little more than cause them to swallow a bubble and float until they manage to burp! (If an axolotl goes to the surface repeatedly to gulp air, something is chemically wrong with the composition of the water in the tank. The likely culprit is a build-up of toxic ammonia.) Distinguishing Gender It is extremely difficult to tell the difference between a male and female axolotl, which can lead to a lot of surprise births in captivity. Any time that you choose to house two axolotls together, most anything can happen, so don’t be surprised if you find eggs in the aquarium.

Determining Sexual Maturity At full sexual maturity, females appear rounder at the end of their bodies, while males are more elongated, with longer tails and a larger cloacal region, but often only an expert can make this distinction. If the vent (the area behind the back legs and under the tail) is examined closely, both genders have a small bump that is actually a cloacal gland. In males, the bump is much larger. In white, golden, and albino axolotls you can tell the animals are fully mature if their toes are dark brown, and the soles of their feet appear to be dirty. Other color types may have darker toe tips, but it’s more difficult to see. Young axolotls will develop to adulthood in 18 months to two years. If well cared for, they can easily live to 15 years of age. Color Variations and Types There are no different types or sub-species of axolotl. Do not let breeders suggest otherwise when you are shopping for a pet. These are highly specialized creatures indigenous only to the area around Mexico City, which largely explains the perils they face in the wild.

Part of their unique nature lies in the fact that they have changed very little in their evolutionary history. The spread of Mexico City has all but erased the axolotl’s native habitat and placed the creatures on the CITES endangered species list. Although conservationists are laboring to create safe havens for them, the axolotl’s ultimate fate in the wild is highly questionable. Known color variations of axolotl include: – gray, – and piebald. Wild specimens are the darkest in color. Each type has a specific name, and often axolotls are sold according to this designation. The names do not, however, denote different species of axolotl. There is only the one type. “Wild” or Brown Shades The brown shades are the most common seen in axolotls, ranging from a warm tan to near black. It is common for the body to exhibit some spotting or speckling and frequently the belly of the salamander is lighter than the back. In sexually mature adults, the toes often become pale. This variety is, however, the most surrealistic looking, and is not as popular among enthusiasts who prefer more dramatic color variations.

Albino and Golden Albino Any animal that is termed an albino lacks skin pigmentation and therefore appears to be white. Albino axolotls, however, can range from cream to yellow, and the body may seem to be shaded. The real telltale sign of albinism, however, is the presence of red eyes. When albinos reach adulthood, their feet and toes are grayer in coloration. Golden Albinos have a lovely, warm tone that can almost seem to glow. Like their paler cousins, however, they have the same red or bright pink eyes. Typically albino axolotls have really beautiful gills that are pink or red, in striking contrast to the pale tone of their bodies. For this reason, their look is even more exotic. Arguably, these are among the most attractive members of this species, and highly popular as pets. Melanoid Axolotls termed “melanoid” do not display the typical shiny areas or “iridophores” generally seen on the body and around the eyes of this species. These specimens are almost jet black, but often with a paler underside and toes, especially as adults.

Leucistic This color variation is easily concerned with the albino axolotl. The skin is very light, but a leucistic axolotl’s skin does contain pigment, and can be speckled with black. When this occurs, the creature is said to be a “piebald.” Also, a leucistic will not have red eyes, and their eyes are generally encircled with a black ring. They are also highly popular as pets because they sport the same pink gills as an albino, if in somewhat more muted shades. Copper Copper axolotls are most commonly found in Australia, where the species is the only non-native salamander that may be kept as a pet. The color is very much like caramel in most individuals, but can be much darker. These axolotls also have red eyes, but that fact is often missed due to the color of the creature’s skin. The gills will be the same color as the salamander’s body. Axolotl Biology Because axolotls are completely aquatic even though they are amphibians, they cannot leave the water to colonize new habitats.

In an odd twist of fate, the fact that they have been cultivated for medical research has saved the axolotl from sure extinction. Now, in addition to their value as a lab animal, they are increasingly prized as exotic pets. Although a carnivore, the axolotl has only pedicalate teeth that look like little cone-shaped stumps. The teeth can be used to grip food and to move it around in the mouth before swallowing, but the meal goes down whole. Even if your axolotl should nip at you, the bite won’t hurt. The little guy just doesn’t have the equipment to do any damage. Like all amphibians, the axolotl has a three-chambered heart and, as mentioned, rudimentary lungs. This is not, however, a typical feature of their kind. The vast bulk of amphibians can live in the water or on land. Axolotls, however, will die if kept out of their aquatic habitat for too long. Regenerative Abilities These salamanders are famous for their ability to regenerate their limbs within a few weeks. Any damaged appendage will form a bud from which a new foot or leg develops.

It is even possible for an axolotl to regrow portions of its spine and brain. Occasionally, this regenerative ability goes awry, and a perfectly healthy axolotl with four functional legs will suddenly grow a fifth appendage. This is nothing to worry about, and could be a consequence of the degree to which axolotls have been inbred in captivity. As long as the axolotl is able to function normally, and can feed, it doesn’t matter how many limbs it does or does not have. If, however, an additional growth or appendage is causing the salamander to suffer, the advice of a veterinarian should be sought. Although no one likes to contemplate intentional cruelty, it must be emphasized that you should never inflict any kind of damage to your axolotl, no matter how minor, for the purposes of witnessing their regenerative powers. Young axolotl heal very quickly, and are often able to replace a lost or damaged limb within a month. Older animals may require several months. The process is not effortless by any means, and becomes more and more difficult as the salamander ages.

Mexican Axolotls, Mexican Axolotl Pictures, Mexican Axolotl Facts - National Geographic Size relative to a tea cup Please add a "relative" entry to your dictionary. The Mexican axolotl (pronounced ACK-suh-LAH-tuhl) salamander has the rare trait of retaining its larval features throughout its adult life. This condition, called neoteny, means it keeps its tadpole-like dorsal fin, which runs almost the length of its body, and its feathery external gills, which protrude from the back of its wide head. Found exclusively in the lake complex of Xochimilco (pronounced SO-chee-MILL-koh) near Mexico City, axolotls differ from most other salamanders in that they live permanently in water. In extremely rare cases, an axolotl will progress to maturity and emerge from the water, but by and large, they are content to stay on the bottom of Xochimilco’s lakes and canals. Close relatives of the tiger salamander, axolotls can be quite large, reaching up to a foot (30 centimeters) in length, although the average size is closer to half that.

They are typically black or mottled brown, but albino and white varieties are somewhat common, particularly among captive specimens. Axolotls are long-lived, surviving up to 15 years on a diet of mollusks, worms, insect larvae, crustaceans, and some fish. Accustomed to being a top predator in its habitat, this species has begun to suffer from the introduction of large fish into its lake habitat. Natural threats include predatory birds such as herons. Populations are in decline as the demands of nearby Mexico City have led to the draining and contamination of much of the waters of the Xochimilco Lake complex. They are also popular in the aquarium trade, and roasted axolotl is considered a delicacy in Mexico, further shrinking their numbers. They are considered a critically endangered species. Pet Axolotls Updated July 11, 2016. What is an Axolotl? The axolotl may not a common pet but it is a very unique one. The axolotl is a type of salamander that is native to Mexico . The scientific name for pet axolotols is Ambystoma mexicanum.

The common pet or laboratory axolotl refers exclusively to A. mexicanum, although in Mexico the term axolotl is used in reference to several species of Ambystoma. The axolotl is neotenic, meaning that it doesn't routinely undergo metamorphosis from the larval to adult form, as happens with most other salamanders. Instead, the larval form (with gills) becomes sexually mature and reproduces, maintaining a strictly aquatic lifestyle. Under some circumstances, the axolotl can undergo metamorphosis into a terrestrial from, although this can be stressful on the animal. The axolotl has amazing regenerative abilities. If an axolotl is injured, even to the point of losing a body part, they will heal readily and even regenerate lost pieces. They are fairly hardy creatures that can be expected to live up to 10-15 years with attention to proper care, particularly with respect to water quality. Their skin and gills are very sensitive and quite soft, so handling is not recommended. Juvenile axolotls can be cannibalistic towards each other, so they are best raised in separate enclosures.

Adults can potentially be housed together but watch for cannibalistic tendencies. Of course, if a body part gets bitten off by a tank mate, an axolotl can regenerate it over time. Housing Axolotls Axolotls can get quite large, so at least a 15-20 gallon fish tank (aquarium) is recommended, although the tank doesn't have to be full of water (the water only needs to be just deeper than the full length of the axolotl). Most owners will find a filtered aquarium easier to maintain. Without a filter the water will need frequent changing. However, if you do choose to have a filter on the tank, the filtration rate should be fairly slow and avoid powerful filters that create strong currents. The filter intake should not be in a position to trap the gills of your axolotl. Safe cleaning would consist of using a siphon to vacuum the bottom of the tank and a 20 percent water change should be done weekly. If you are not using a filter, you will have to do a 20 percent water change every day or every other day.

Never do a full water change as this creates a situation where the water chemistry changes too drastically for your pet axolotl. Tap water should have any chlorine or chloramines (added during the water treatment process) removed using commercially available solutions. Never use distilled water and the pH of the water should be 6.5-7.5 (neutral). If gravel is used on the bottom of the tank it needs to be coarse gravel. Fine gravel might be ingested during feeding. Some owners opt to simply leave the bottom of the tank bare, although others believe this may stress the axolotls a bit since they can't get a foothold on the bottom of the tank that way. The tank should be kept in a cool room away from bright sunlight. The water temperature should be kept cool, between 57-68 degrees Fahrenheit (14-20 degrees Celsius), and never above 75 degrees Fahrenheit (24 degrees Celsius). No special lighting is required, and in fact a place to get out of the light may be appreciated, such as a half flower pot or aquarium type castle.

Feeding Axolotls In the wild, axolotls feed on snails, worms, crustaceans, small fish, and small amphibians. In captivity, they can be fed brine shrimp, small strips of beef or liver, earthworms (wild caught worms can carry parasites), bloodworms, tubifex worms ( often fed to fish ), or commercial fish pellets (e.g. salmon or trout pellets). If feeding these fresh items it is best to feed a variety to get a better balance in the diet. You can also get special axolotl feeding pellets from the Indiana University Axolotl Colony . Uneaten food should be cleaned from the tank daily. Terrestrial Axolotls Axolotls do occasionally undergo metamorphosis to take on the terrestrial form (land dwelling). The conditions under which this would happen naturally is poorly understood. They can be induced using changes in water characteristics, or by supplementing with certain proportions of thyroid hormone . Of course the terrestrial form of the axolotl has a completely different set of care requirements. Trying to induce metamorphosis is not recommended, as this can place undue stress on the creature, and can significantly shorten its life span.

Axolotls are used fairly extensively in laboratory settings, primarily to study their regenerative capabilities, and are relatively easy to breed in captivity. Unfortunately, wild axolotls are now considered critically endangered, suffering from the effects of a shrinking habitat, exploitation, pollution, and introduction of non-native predators. Edited by Adrienne Kruzer, RVT Axolotls - Housing in Captivity Housing Axolotls in Captivity General Info The Requirements Page and Health Page discuss several important points that are mentioned on this page. For information regarding the housing of tiger salamanders and metamorphosed axolotls , click that link. Axolotls are not demanding in respect to their accommodation. It's important to bear in mind that an adult axolotl can reach a size from 18 to 35 cm in length (7-14 inches). Laboratories prefer to use minimalistic containers that barely allow the animals to turn around, like fish bowls. Each one is used to house a single animal, or a few are housed together in a container that approximates to a 45 cm long aquarium (18 inches).

For the enthusiast, the accepted minimum size would be a 45 cm long aquarium (US 10 gallons) for one adult. The Simple Aquarium Shown below is an example of a simple setup for one adult axolotl. 1) Homemade mesh lid (removed for photograph); 2) Thermometer; 6) Hide area; 7) Bare tank bottom (no gravel). This is an aquarium of dimensions 50 cm long x 25 cm wide x 25 cm tall (20 x 10 x 10 inches; standard 10 gallons). It has no lighting, but does normally have a lid to prevent leaping. The hides consist of a pot and artificial plants. The filter is a hang-on-back waterfall filter, and the outflow is dispersed by a rock to prevent a current. No bottom substrate is used. The Advanced Aquarium For multiple axolotls, a larger tank is required. Shown below is an attractive example that could easily house 6 adult axolotls. At the time of this photo, it contained 12 juvenile axolotls.

1) Lid (glass plates with handles); 2) Thermometer; 5) Many hides and live plants; 6) Fine sand substrate; 7) Foam layer and sturdy tank support. This is an aquarium of dimensions 150 cm long x 35 cm wide x 45 cm tall (5 ft x 14 in x 18 in). It has fluorescent lighting and glass lids. Hides consist of rocks, pottery, driftwood, and live plants (ambulia, water sprite, valls, liliopsis and java moss). The filter is an under-tank canister. The filter intake and outflow are on opposite ends of the tank to improve filtration. The outflow is dispersed by a spray bar to reduce stress to the axolotls. The bottom substrate is fine black sand (grain size 1 mm or smaller). An aquarium this size weighs over 400 kg (800 lb); large aquariums need a very sturdy support underneath. A layer of foam under the tank will help to even out any irregularities in the support. Filtration Filtration is not essential for axolotls, provided you're willing to change the water very frequently.

Most hobbyists prefer to include a filter, and there are a number of options, including under-gravel filters, internal power filters, external "hang-on-the-tank" filters, and canister filters. I prefer the last type, but it is also the most expensive option. Axolotls excrete a lot of waste. This is mainly in the form of ammonia (NH3). Ammonia is a very toxic substance in its unionised form, NH3, but this is in constant equilibrium with the ionised form NH4+, and through the process of nitrification, it is converted into the less harmful substance nitrite (NO2-). Other bacteria then convert this into the much more benign substance nitrate (NO3-). These two processes comprise the most important aspects of what is known as biological filtration. Nitrate is a source of fixed nitrogen (i.e., not Nitrogen gas, N2) for plants and fungi. Live plants, if included in the tank, will consume the nitrate generated from a good filtration system. I discuss water quality and chemicals in more detail on the Requirements Page .

In my years of experience with aquarium filters and axolotls, I have found that it is important to choose a filter that is correctly sized for filtering the aquarium's water volume. A large filter is not suitable for a small tank and will usually create far too much water flow in the tank. This is possibly the biggest cause of stress-related disease in axolotls. Obviously the tank shouldn't be like a river, but the actual water turnover through the filter shouldn't be much beyond what is required. Too little "biological filtration" - roughly surface area for bacteria growth in the filter - is also a bad idea. The filter shown at right is an Eheim "Ecco" 2231. To my knowledge, it's their smallest canister filter, designed for aquariums from 60 to 100 litres (13-22 Imp gal, 11-18 US gal). It has a turnover of 300 litres per hour (66 Imp gal, 50 US gal). I've turned this down to about 150 litres per hour. As shown in the aquariums above, it is important to disperse the outflow from the filter.

This can be accomplished by means of a spray bar, or the careful placement of aquarium decor to interrupt the flow of water. Whether you use a power filter (internal or external), an under-gravel filter, or something above-board is up to you, but there are a few more things to keep in mind. If you don't use gravel, you may need a slightly larger filter to provide more surface area on which bacteria can grow. These bacteria will make up the biological side of your filter, and need to have a sufficient surface area on which to grow in order to meet the demands made on them. You can buy filter media that is porous, and therefore has a surprisingly large surface area for bacteria. Eheim's "Ehfi-Substrat" is a sintered glass that performs this function. I use it in combination with the 2231's standard filter pads. Other companies like Fluval also supply similar filter media. Finally, remember, you should "age" the tank for at least two weeks after filling it with water, connecting up the filter, and before adding many axolotls.

The addition of a single small axolotl after initial setup will aid development of the bacteria on the filter media, in preparation for the addition of your other axolotls. Obviously, water should be dechlorinated with aquarium dechlorinator (or better still, left to stand for several days). More on water on the Requirements Page . Due to my experience (and impatience!), I rarely age my own aquariums. Instead, I add my axolotls almost immediately, but I clean the tank and do a partial water change daily for two weeks. For the following few weeks or so I make slightly less regular water changes, in order to give the filter a chance to build up to full capacity. Once your filter is established for a month or two, continue to conduct regular, if less frequent, water changes. I recommend changing between 10 and 20 percent of the tank's water volume every week, depending on how densely it is populated. I also advise that you vacuum up any uneaten food and unfiltered waste after every feeding (or at least twice per week), and replace the water removed. A small siphon is ideal for this purpose.

Substrates Axolotls have a nasty habit of getting normal aquarium gravel in their mouths, and occasionally swallowing it. This can be fatal because the gravel can cause blockages in the gut. It's rare, but not rare enough to be worth risking. In short, if you use normal aquarium gravel you risk killing your axolotl. Gravel-swallowing can be avoided by using gravel that is very large (larger than the animal's head). If you use an external filter like me, stones tend to let debris accumulate in the tank, and so the filter has a hard time keeping the the bottom clear of solids. Since axolotls are messy, the filter may difficulty dealing with the excrement and waste food that accumulate in gravel. If you do use gravel, it's advisable to siphon the waste out of it - a "gravel cleaner" is ideal for this purpose. As another alternative, fine sand is also a good substrate, as it will not clog the digestive tract if ingested. It has been my experience that axolotls can't "grip" the bottom of a glass tank. Some people feel that this is stressful for the animal.

Plastic tanks don't suffer from this problem so much because no plastic is as smooth as glass. Other alternatives for substrate include flat pieces of slate covering a large portion of the tank bottom, gravel that is glued into the bottom of the tank using aquarium sealant, or a simple layer of dark-colored aquarium sealant in the bottom of the tank. Aquarium sealant should always be allowed to cure thoroughly before water is added to the tank. Lids and Lighting Axolotls do not require any specific lighting, but lighting is essential for a display aquarium, and a must for an aquarium that contains live plants. Many successful axolotl enthusiasts use ordinary aquarium lighting - typically, a "hood" with a fixture for a fluorescent aquarium bulb. A lid is required, regardless of the type of lighting used. Axolotls cannot climb, but they have been known to leap out of their tank, often with fatal consequences. If a mesh lid is used, this may help to keep water temperature lower by allowing evaporation. The addition of a fan blowing on the water can further reduce water temperature significantly. Temperature Always use an aquarium thermometer. The water should be kept between 10 and 20 °C (50-68 °F).

Anything below about 10 °C leads to more sluggish activity and a lower metabolism. At lower temperatures, axolotls will eat less frequently. They may even refuse food altogether. It should be noted though that axolotls don't "hibernate" in the sense applied to most animals - they simply have reduced metabolism. Above 24 °C, axolotls become stressed, and such warm conditions will usually result in disease if sustained for a several days. Temperature fluctuations of more than a few degrees Celsius in a 12 hour period (between night and day) can also be stressful. It's a good idea to keep the temperature stable on a day-to-day basis, even if it varies over the year with the seasons. A heater is rarely ever necessary. If needed, standard aquarium heaters used in fish aquariums are ideal for axolotl tanks. A heater set at 18 °C (65 °F) is a good idea in a room that's very cold, particularly if there is a risk of freezing. More often, the hobbyist is faced with the problem of keeping the aquarium cool enough during warm weather.

While whole-room air conditioners and aquarium chillers are expensive, they are the most-effective ways to significantly decrease the temperature of aquarium water. Read more about cooling methods for aquariums over at Caudata Culture . Decorations The addition of plants, caves, pipes, etc., gives axolotls an added sense of security, as well as being attractive to the human eye. Live plants are a challenge, as axolotls will tend to uproot them. However, floating plants do well, and some plants can be rooted in small pots or in places where the axoltls are less likely to disturb them. While not demanding, axolotls deserve to be well cared for, just like any other animal. Good luck with your aquarium plans. If you have questions about your proposed setup, why not talk to the people in the Axolotl area of Caudata.org's Forum ? You will also find many ideas for axolotl aquaria there. Unless cited in the Acknowledgements , all text and images are ©1999-2012 John P. Clare. All Rights Reserved. The use of any site content without written agreement with the copyright holder is prohibited by International Copyright Law.

ADW: Ambystoma mexicanum: INFORMATION 7513.12 ft Physical Description Axolotls are paedomorphic or neotenic aquatic salamanders, meaning they retain certain larval characteristics in the adult, reproductive state. They possess feathery external gills and finned tails for swimming. Laboratory animals exist in several color morphs, ranging from wild type (dark, mottled brownish-green) to albino. Axolotls reach lengths on average of 20 cm (9 inches), but can grow to more than 30 cm (12 inches) in length. ( Brunst, 1955a ) The sexes can be easily distinguished in adult axolotls. Males can be identified by their enlarged cloaca (similar to other urodeles), while females have a smaller cloaca and round, plump bodies. ( Brunst, 1955a ) Other Physical Features 9.06 in Development A. mexicanum is paedomorphic, which means that it retains larval characteristics in the reproductively mature adult form.

Juvenile and adult axolotls possess feathery, external gills and tail fins suited to an aquatic lifestyle. Metamorphosis can be induced in axolotls via thyroid hormone injections. In the wild, axolotls rarely, if ever, metamorphose. Development - Life Cycle metamorphosis Reproduction The courtship behavior of A. mexicanum follows the general Ambystoma pattern; it first involes each animal nudging the other's cloacal region, eventually leading to a "waltz," with both animals moving in a circle. Next, the male moves away while undulating the posterior part of his body and tail (resembling a "hula dance"), and the female follows. The male will deposit a spermatophore (a cone-shaped jelly mass with a sperm cap) by vigorously shaking his tail for about half a minute, and will then move forward one body length. The female then moves over the spermatophore, also shaking her tail, and picks up the spermatophore with her cloaca.

( Eisthen, 1989 ) Mating System polygynandrous (promiscuous) Axolotls breed in the wild generally from March to June. From 100 to 300 eggs are deposited in the water and attached to substrates. Eggs hatch at 10 to 14 days and the young are immediately independent. Sexual maturity is reached in the next breeding season. ( Eisthen, 1989 ) Key Reproductive Features zooplankton Predation Axolotls may be preyed on by large fish and conspecifics. Large fish have only recently been introduced into the lakes where axolotls are found, contributing to the demise of their populations. Ecosystem Roles Axolotls were the top predator in their native environment, making them important in structuring community dynamics. Economic Importance for Humans: Positive Axolotls are an important research animal and have been used in studies of the regulation of gene expression, embryology, neurobiology, and regeneration.

Occasionally taken as a food item (substituted for fish), axolotls are prepared by either roasting or boiling and the tail is eaten with vinegar or cayenne pepper. They have also been used for medicinal purposes. ( Smith, et al., 1989 ; Brunst, 1955a ) Positive Impacts Appendix II Other Comments The word "axolotl" comes from the native Aztec language, or nahuatl. It roughly translates to: water slave, water servant, water sprite, water player, water monstrosity, water twin, or water dog. All of these names refer to the Aztec god Xolotl, brother to Quetzacoatl and patron of the dead and ressurrected (where he took the form of a dog), games, grotesque (read: ugly) beings, and twins. Aztec lore states that Xolotl transformed himself into, among other things, an axolotl to escape banishment. He was captured, killed, and used to feed the sun and moon.

( Shaffer, 1989 ; Smith, 1969 ) Larvae of other ambystomids, such as the larval stage of the tiger salamander, A. tigrinum , are often erroneously referred to as axolotls. The name axolotl should be used only when referring to A. mexicanum and not to any other ambystomid salamander. Historically, the Mexican axolotl has been listed under more than 40 different names and spellings; all, except A. mexicanum, have been rejected by the International Commission on Zoological Nomenclature (ICZN). ( Brunst, 1955a ; Brunst, 1955b ; Smith, 1969 ; Smith, et al., 1989 ) The closest relative of A. mexicanum is thought to be A. tigrinum , the tiger salamander. Indeed, the larvae of these species are visually very similar.

Some even consider the axolotl to be a subspecies of the tiger salamander; viable offspring can be produced between the two species in the laboratory, though no hybrids have as of yet been discovered in the wild. ( Brandon, et al., 1989 ; Smith, 1969 ; Smith, et al., 1989 ) Axolotls are excellent lab specimens as they are easy to raise and inexpensive to feed. They are renowned for their amazing regenerative capabilities, have been used widely in developmental studies, and, because of their large cells (they are polyploid), are often used in histological studies. ( Brunst, 1955a ; Smith, et al., 1989 ) Nearly all modern laboratory axolotls can be traced back to 33 animals shipped from Xochimilco to Paris in 1864. They are one of the most widely used and studied laboratory animals. ( Smith, 1969 ; Smith, et al., 1989 ) Contributors Tanya Dewey (editor), Animal Diversity Web. Amy Majchrzak (author), Michigan State University.

Glossary Neotropical living in the southern part of the New World. In other words, Central and South America. bilateral symmetry having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria. carnivore an animal that mainly eats meat chemical uses smells or other chemicals to communicate diurnal active during the day, 2. lasting for one day. drug a substance used for the diagnosis, cure, mitigation, treatment, or prevention of disease ectothermic animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature electric uses electric signals to communicate fertilization union of egg and spermatozoan food A substance that provides both nutrients and energy to a living thing. freshwater mainly lives in water that is not salty. insectivore An animal that eats mainly insects or spiders. internal fertilization fertilization takes place within the female's body iteroparous offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction).

Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes). metamorphosis A large change in the shape or structure of an animal that happens as the animal grows. In insects, "incomplete metamorphosis" is when young animals are similar to adults and change gradually into the adult form, and "complete metamorphosis" is when there is a profound change between larval and adult forms. Butterflies have complete metamorphosis, grasshoppers have incomplete metamorphosis. molluscivore eats mollusks, members of Phylum Mollusca motile having the capacity to move from one place to another. natatorial animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.) References Encyclopædia Britannica Premium Service. 2003. Xochimilco. Encyclopaedia Britannica. Accessed 06/13/03 at . Brandon, R., J. Armstrong, G. Malacinski. 1989. Natural history of the axolotl and its relationship to other ambystomid salamanders. Pp.

13-21 in Developmental biology of the axolotl. New York, NY: Oxford University Press, Inc.. Brunst, V. 1955. The axolotl (Siredon mexicanum) I. As material for scientific research. Laboratory Investigation, 4: 45-64. Brunst, V. 1955. The axolotl (Siredon mexicanum) II. Morphology and pathology. Laboratory Investigation, 4: 429-449. Eisthen, H. 1989. Courtship and mating behavior in the axolotl. Axolotl Newsletter, 18: 18-19. Shaffer, H. 1989. Natural history, ecology, and evolution of the Mexican "axolotls". Axolotl Newsletter, 18: 5-11. Smith, H. 1969. The Mexican axolotl: some misconceptions and problems. BioScience, 19: 593-597. Smith, H., J. Armstrong, G. Malacinski.

1989. Discovery of the axolotl and its early history in biological research. Pp. 3-12 in Developmental biology of the axolotl. New York, NY: Oxford University Press, Inc..

Question: What sort of creature is the axolotl?
Answer: THE SALAMANDER